JPH0614923Y2 - Pouring nozzle for twin-belt continuous casting machine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a pouring nozzle in a twin belt type continuous casting apparatus for continuously obtaining a slab from molten metal.

[Conventional technology]

FIG. 7 shows a conventional twin belt type continuous casting apparatus for continuous casting of thin slabs. 1,1 'is a pair of belts made of metal (mainly steel), 2,2' is a belt driving roll, 3,3 'is a belt positioning top roll, and 4,4 is a belt meandering prevention. It is a steering roll to do. 5,5 'is a belt
It is a water cooling pad for cooling 1,1 'from the back side. 20
Is a molten metal holding ladle, 6 is a tundish for molten metal, 7 is a pouring nozzle, 8 is a molten metal surface, and 9 is a slab cast piece.

In the twin-belt continuous casting machine with such a configuration, the endless metal belts 1,1 'are driven rolls.
It is driven at a constant speed by 2, 2'in the direction shown by the arrow in the figure, and both belts 1, 1'are spaced from the belt positioning top rolls 3, 3'to the belt driving rolls 2, 2 '. In a portion where C is kept parallel to each other and runs downward, a molten metal surface 8 having a rectangular cross section is formed between these belts 1 and 1'and a side mold (not shown) located at the belt end. It is formed. A pouring nozzle 7 is set between the molten metal surfaces 8, and molten metal is continuously injected from the tundish 6 by the pouring nozzle 7.

A belt that is driven endlessly and is in contact with molten metal 1,
Since the back surface of 1'is cooled by the water cooling pads 5 and 5'as described above, the molten metal injected between the belts 1 and 1'is successively cooled and solidified to form the slab slab 9.

[Problems to be solved by the invention]

Since a wide immersion flat nozzle is used as the conventional pouring nozzle 7 as shown in FIG. 7, the belt interval C corresponding to the slab thickness is narrowed (for example, 50
mm or less), there was a problem such as occurrence of melt solidification phenomenon and nozzle clogging phenomenon between the belt and the outer wall of the nozzle.

The present invention intends to provide a pouring nozzle for a twin-belt type continuous casting apparatus which solves such problems.

[Means for solving problems]

The present invention has a plurality of holes vertically penetrating a pouring nozzle in a twin-belt type continuous casting apparatus for pouring molten metal between a pair of belts that move in parallel and move downward. And a cross section parallel to the surface of the molten metal between the belts is partitioned by thin partition walls.

[Action]

In the present invention, since the pouring nozzle has a honeycomb structure, the thickness of the partition wall can be reduced, and thus the pouring nozzle having excellent thermal shock resistance can be obtained.

Further, since the molten metal flows into a plurality of vertically penetrating holes to be cast, a uniform laminar flow is formed in the holes, and uniform casting with less molten metal scattering is realized.

As mentioned above, since the partition wall of the pouring nozzle can be made thin, the width of the pouring nozzle can be made thin according to the belt interval, so that the pouring nozzle and the belt can be spaced sufficiently, It is possible to prevent the solidification phenomenon from occurring.

At the same time, by thinning the partition wall of the pouring nozzle, the outer wall is also heated by the heat of the molten metal passing through the pouring nozzle hole, which prevents solidification on the outer surface of the pouring nozzle.

Furthermore, even if the width of the belt is narrowed, the cross-sectional area of the pouring nozzle can be made large by thinning the partition wall as described above, which enables quiet pouring and the same casting amount. If so, the width of the pouring nozzle can be reduced and the cast piece can be made thinner.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIGS.

In the twin-belt type continuous casting apparatus shown in these drawings, the same parts as those of the conventional twin-belt type continuous casting apparatus shown in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 10 is a nozzle having a honeycomb structure, which is attached to the tip of a tundish nozzle 12 provided at the lower end of a tundish 13 which receives the molten metal from the ladle 20 for holding the molten metal, and is attached to the meniscus surface (molten metal surface) 50-50. It is placed at a position where it is immersed for about 100 mm. This tundish nozzle
Nozzle 10 attached to the tip of 12 is composed of a refractory material having a honeycomb structure having a plurality of square holes 11 penetrating vertically and having a thin partition wall in a cross section parallel to the molten metal surface. It will be hot water. The shape of the nozzle 10 having a honeycomb structure is selected depending on the molten metal flow rate and the pouring time, but the thickness of the partition wall frame of this refractory material is approximately 5 mm or less, and the belt spacing is
At 30mm, the frame thickness is about 1.5mm. Again hole 1
The size of 1 is 7 mm ^□ , which is arranged in two rows in the thickness direction of the slab. In addition, as a material for the pouring nozzle of the refractory material having the honeycomb structure, zirconia (ZrO ₂ + Y ₂
O ₃ ), alumina (A ₂ O ₃ ), or zirconia graphite mixed with some graphite, alumina graphite, or the like can be used.

The present embodiment is configured as described above, the molten metal,
Flows through the tundish nozzle 12 to the honeycomb nozzle 10, and is cast from the upper molten metal nozzle 10 that has become a uniform laminar flow when passing through the plurality of holes 11 of the pouring nozzle 10, so that the molten metal does not scatter uniformly. It can be carried out.

Further, since the refractory pouring nozzle 10 has a honeycomb structure and has sufficient strength even if the partition walls are thin and has thermal shock resistance due to the thin partition walls, the belts 1, 1 ' Since it can be thinned according to the interval of,
The pouring nozzle 10 can maintain a cross-sectional area required for pouring, and the pouring nozzle 10 and the belts 1 and 1'can be sufficiently spaced from each other to further prevent the molten metal solidification phenomenon. At the same time, by thinning the partition wall of the pouring nozzle 10, the pouring nozzle
The outer wall of 10 is heated up to a temperature close to that of the molten metal by the molten metal flowing in the hole 11, so that solidification of the molten metal on the outer surface of the nozzle can be prevented.

Furthermore, the conventional pouring nozzle usually requires a hole diameter of 10 mm or more in order to prevent the nozzle from being clogged due to the influence of inclusions, etc. Since it is very thin as described above, it is heated to near the temperature of the molten metal, and there is an advantage that even if the size of the hole 11 is reduced, clogging due to inclusions does not occur.

Therefore, it is difficult to cast a thin slab having a thickness of 50 mm or less with the conventional nozzle, but in the present embodiment, a thin slab having a thickness of 30 mm is possible.

Element test examples relating to this example are shown in FIGS. 4 and 5.
It will be described with reference to the drawings. As shown in the figure, a refractory pouring nozzle with a honeycomb structure was made of ZrO ₂ (+ Y ₂ O ₃ ) quality material, and 1 TON of ordinary steel was poured to confirm its effectiveness. The apparatus used is as shown in FIGS. 4 and 5, and the dimensions and the like are shown in the figures. In addition, a U-shaped molten metal passage as shown in the drawing was formed around and below the refractory nozzle so that the molten metal could flow in the direction of the arrow.

With this device, approximately 800 refractory nozzles with a honeycomb structure can be
After preheating to ℃, it was poured. As a result, it was found that a thin slab with a thickness of 30 mm could be cast without any problems.

Another embodiment which can be adopted as the honeycomb structure of the pouring nozzle is shown in FIG.

That is, the one shown in FIG. 6 (a) has square holes 11a arranged in a line in the length direction of the slab, and the one shown in FIG. 6 (b) has round holes 11b with the length of the slab. They are arranged in a line in the direction.

In the above embodiment, the honeycomb structure has a plurality of holes that penetrate the quadrangle or the circle in the vertical direction, but holes having a triangular, hexagonal, or elliptical shape may be provided. Further, what is referred to as a honeycomb structure in the present specification is not a narrow sense composed of hexagonal holes surrounded by partition walls, and one having a plurality of non-hexagonal holes formed by partition walls as described above may also be used. It means the broad meaning included.

[Effect of device]

 The present invention can bring the following effects.

(1) The pouring cross-sectional area of the nozzle can be made large, and since pouring is performed by flowing through a plurality of holes of the pouring nozzle having a honeycomb structure, quiet pouring is possible.

(2) Since the thickness of the partition walls of the honeycomb structure of the pouring nozzle can be made thin, the thermal shock resistance is high, the molten metal does not solidify on the outer surface of the nozzle, and continuous casting of a thin slab is possible.

[Brief description of drawings]

FIG. 1 is an elevational view of the first embodiment of the present invention, FIG. 2 is an elevational view of the main part of the apparatus, and FIG. 3 is an AA arrow view of FIG.
FIG. 4 is an explanatory view of the test apparatus of the first embodiment, FIG. 5 is a view as seen from the arrow BB in FIG. 4, and FIG. 6 is a pouring of honeycomb structure as another embodiment of the present invention. FIG. 7 and FIG. 7 are explanatory views of a conventional twin belt type continuous casting apparatus. 1,1 ′ …… Metal belt, 2,2 ′ …… Belt drive roll, 3,3 ′ …… Top roll, 4,4 ′ …… Steering roll, 5,5 ′ …… Water cooling pad, 8 …… Pouring surface (meniscus), 9 ... Slab slab, 10 ... Honeycomb structure refractory nozzle, 11, 11a, 11b ... Honeycomb hole, 12 ... Tundish nozzle, 13 ... Tundish, 20 ... … Ladle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Yamane 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Ltd. Hiroshima Research Laboratory (72) Instructor Toru Nishimura 4-chome, Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture 6-22 No. 22 in Mitsubishi Heavy Industries, Ltd. Hiroshima Works (56) Reference JP-A-61-289953 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A twin for continuously obtaining a slab by pouring molten metal between a pair of belts which are parallel to each other and move downward.
Twin-belt continuous, characterized in that the pouring nozzle in the belt-type continuous casting device has a plurality of holes penetrating vertically and has a honeycomb structure in which the cross section parallel to the molten metal surface between belts is divided by thin partition walls. Pouring nozzle for casting equipment.